PF-4840154 is a pyrimidine derivative discovered by Pfizer at its Sandwich, Kent research center. The compound is a potent, selective activator of both the human (EC50 = 23 nM) and rat (EC50 = 97 nM) TRPA1 channels.[1] This compound elicits nociception in a mouse model through TRPA1 activation. PF-4840154 is used as a reference agonist of the TRPA1 channel for in-vitrohigh-throughput screening purposes, and is superior to allyl isothiocyanate for this use.[2] The TRPA1 channel is considered an attractive pain target based on the fact that TRPA1 knockout mice showed near complete attenuation of pain behaviors in some pre-clinical development models.[3][4]